How to get selected columns from the database using $wpdb->get_results(); - wordpress

Question

I'm looking for a solution in $wpdb->get_results() which is equivalent PDO::FETCH_NUM.
This is what I'm trying to achieve:
function get_data( $token, $field ){
global $wpdb;
$wpdb->show_errors();
$result = $wpdb->get_results('SELECT '.$field.' FROM ' . $this->get_table(). ' WHERE token =\''.$token.'\' ORDER BY id DESC');
return $result[0];
}
As you can see from my query above, I'm selecting specific columns from the database, but I don't know how to access selected column using $wpdb->get_results();
I would like to get the value of the $field column based on the where clause criteria.

Answer 1

After deep research I have gotten a solution.
Basically, this is how to get the $field column.
function get_data( $token, $field ){
global $wpdb;
$wpdb->show_errors();
$result = $wpdb->get_results('SELECT '.$field.' FROM ' . $this->get_table(). ' WHERE token =\''.$token.'\' ORDER BY id DESC');
$data = "";
foreach ($result as $key => $value) {
$data = $value->$field;
}
return $data;
}
To make it simple, let's assume you have a column called first_name, this is how to get the first_name column from the database.
function get_data( $token ){
global $wpdb;
$wpdb->show_errors();
$result = $wpdb->get_results('SELECT first_name FROM your_table_name WHERE token =\''.$token.'\' ORDER BY id DESC');
foreach ($result as $key => $value) {
echo $data = $value->first_name;
}
}